Preheat oven to 375 degrees F.
Sift flour, baking powder, and salt together in a medium bowl, and set aside.
In the bowl of a stand mixer or in a large bowl using a hand mixer, cream the butter. Add the sugars and beat until well blended. Add the yolk and vanilla and mix until well combined.
Add the dry ingredients to the wet ingredients alternately with the milk by adding half of the dry mixture, 1 teaspoon of milk, then repeating.
Stir in food coloring liquid/gel and mix to achieve desired color.
Add the dough to the barrel of a cookie press fitted with your disk shape of choice and press the cookies onto ungreased cookie sheets.
Bake for 6-10 minutes, depending on the shape of the cookie and how brown you prefer them. Remove to a wire rack to cool. Store at room temperature in an airtight container.